Grinding machine for all kinds of material, e. g. waste or wood

ABSTRACT

The invention relates to a grinding machine for all kinds of material, the machine comprising: a receiving element for the material ( 5 ); at least one shaft ( 2 ) positioned in the housing ( 1 ) and provided with grinding tools ( 3 ); rigid cutting tools ( 4 ) which are arranged in the housing ( 1 ) and against which the grinding tools ( 3 ) operate, grinding the material ( 5 ) with specifically low forces. To this end, the grinding tools ( 3 ) comprise cutting regions ( 3.1,3.2 ) within which an inner cutting region ( 3.1 ) can take a large amount of material ( 5 ) to be ground and grind the same, thus comprising a small lever arm, and an outer cutting region ( 3.2 ) can take a smaller amount of material ( 5 ) to be ground and grind the same, thus comprising a large lever arm. According to the invention, the rigid cutting tools ( 4 ) are provided with teeth ( 4.2 ) having profiles ( 4.3 ) which cooperate with one of the cutting regions ( 3.1, 3.2 ), a first transversal edge ( 3.4 ) of the grinding tools ( 3 ) being oriented towards a second transversal edge ( 4.4 ) of a tooth ( 4.2 ) of the rigid cutting tools ( 4 ) in such a way that it cuts past the same.

The invention relates to a comminution machine for all kinds ofmaterial, for example waste, such as domestic waste and bulky waste, orwood, comprising a receiving element for the material, provided in ahousing, at least one driven shaft, on which comminution tools areprovided, and rigid cutting tools arranged in the housing as opposingtools for the comminution tools for comminuting the material.

PRIOR ART

Comminution machines of this type have been disclosed under thedesignation “Zerreiβer” [shredders].

Following an overall view of the prior art, an apparatus which has thegroups of features described below may be assembled for the comminutionmachine outlined only generically at the start.

According to EP 0 521 081 B1, as is known the comminution tools areformed by U-shaped knives, which are located in a plane at right anglesto the axis of rotation for the shafts and which are arranged uniformlyalong and around two substantially parallel and horizontal shafts, whichare driven by a motor which can drive the shafts in opposite directions,and which have a mutual spacing which is somewhat greater than twice thespacing between the radial outer point of a knife and the axis ofrotation. The drive apparatuses are provided between the motor and theshafts.

The material is fed to the knives through a shaft arranged above theknives. These knives interact with knives fixed in a stationary mannerbetween the shafts on part of the frame of the apparatus for materialcomminution when the shafts rotate in opposite directions, which meansthat the cutting edge of the blades are moved toward one another on thetop side of the stationary knives.

For this purpose, as previously known from the earlier prior art, themutual spacing between the two shafts is a fixed spacing.

The drive devices comprise, likewise in a previously known way, asuitable gearbox for each of the two shafts, a hydraulic motor withadjustable rotational speed for driving each shaft, an adjustable pumpfor supplying each hydraulic motor and gearbox, by means of which themotor drives the pumps, which are able to reverse the flow through thehydraulic motors in order to rotate each shaft individually forward andbackward in accordance with a predetermined sequence.

From the invention according to EP 0 521 081 B1, it is possible togather that it is important for each knife to comprise two substantiallyU-shaped blades arranged one behind the other, for the radially outerand front parts of the two blades, seen in the direction of rotation ofthe cutting movement of the knives, to be constructed as substantiallytangentially oriented wedges, for the spacing between the axis ofrotation and the wedge of the front blade to be shorter than the spacingbetween the axis of rotation and the wedge of the following blade, andfor the radially outer contour of the following blade to correspondsubstantially to a segment of a spiral line around the axis of rotation.

For this purpose, in a functional combination, the features of thecomminution machine corresponding to EP 0 928 222 B1, which is of thegeneric type, can be supplemented in order to obtain a functioning unit.

Accordingly, the stationary knives are formed by a previously knowncutting table, which is arranged at the bottom of a hopper having atleast one set of fixed, parallel lower knives, which are separated fromone another by openings through the table.

Furthermore, at least one rotatable shaft of a drive unit is provided inknown manner, which shaft is arranged above the cutting table in adirection which extends at right angles to the lower knives.

Finally, as is known, there is a number of disk-like upper knives, whichare fixed to the shaft, of which each knife is provided with a number ofteeth and which extends partially downward into each of their openingsin the table. Each opening is wider than the associated upper knifewhich, in addition, is arranged close to one of the lower knives in theassociated opening.

According to the invention disclosed there, it is important that thelower knife extends in a direction which intersects the axis of theshaft or a region around the latter, in relation to this design it beingassumed that, according to DK 169 378, a cutting table whose planealready extends underneath the shaft is already known.

In this case, on each side of the shaft there is arranged a set of aplurality of knives, whose arrangement in relation to one another formsa V or an inverted V.

The respective cutting edges can be designed to be curved or wavy.

By means of the constructional improvement according to EP 0 928 222 B1of the cutting table divided into knives, in which the plane of thecutting table intersects the axis of the shaft, the intention is for thematerial to be comminuted with an advantageous cutting angle of about90°.

A comminution machine for materials, such as organic waste, bulky wasteor the like, assembled in this way in accordance with the documentedprior art and described above, in spite of a tried and tested function,still exhibits disadvantages, which consist in particular in the factthat

-   -   the stability of the comminution tools fitted to the shaft is        endangered,    -   the effectiveness of the comminution process is limited by the        stationary knives,    -   the throughput cannot be increased, because of the action of the        shape of the comminution tools on the shaft, in interplay with        the stationary knives, forcing material away, and    -   the power consumption of the machine is relatively high.

SUMMARY OF THE NUB OF THE INVENTION

The invention is based on the object of providing a comminution machinefor all kinds of material, for example waste, such as domestic waste andbulky waste, or wood, in particular organic waste, bulky waste, such asrefrigerators, tires, furniture, carpets, mattresses, tree stumps,demolition timber or similar materials, which comprises

-   -   a receiving element for material, provided in a housing,    -   at least one shaft, on which comminution tools are arranged,    -   rigid cutting tools which are fitted in the housing, whose        cutting edges in the extension just to do not intersect the axis        of the shaft or a region around the axis, against which rigid        cutting tools the comminution tools of the shaft comminute the        material put in.

Thus, in interplay between the comminution tools acting in oppositedirections of rotation with the rigid cutting tools, the waste is alwaystaken in a differentiated manner, is conveyed and, fixed against therigid cutting tools, is comminuted with specifically low forces.

On one hand, the comminution machine must be configured for production,operation, maintenance and repair in subassemblies suited for thispurpose and, on the other hand, must be capable of control to theconditions of the comminution process.

As a result of the object to be achieved,

-   -   the stability of the comminution tools of the shaft is to be        increased,    -   the level of comminution is to be increased by means of        constructional changes in the rigid cutting tools,    -   the throughput of the machine is to be increased,    -   the power consumption of the machine is to be reduced,    -   the ability to comminute in particular ductile,        non-brittle-fracture materials, such as plastic and plastic        film, is to be promoted and    -   the material present in the receiving area and to be comminuted        directly is to be fed completely to the available cutting        geometries        and these objects are to be satisfied as advantages which act in        their entirety as compared with the prior art.

According to the invention, this is achieved in that

a) the comminution tools, seen respectively in a direction of rotationof the shaft and in their cross section, have at least two cuttingregions, of which at least an inner cutting region is able to take andcomminute more material to be comminuted and has a relatively shortlever arm for this purpose, and also at least one outer cutting regionis able to take and comminute less material to be comminuted and has arelatively long lever arm for this purpose, the cutting contours of bothcutting regions forming a circular arc about the axis of the shaft inthe direction of the axis of the shaft,

b) the rigid cutting tools have a number of teeth arranged in a mannerof a saw and thus two flanks of the teeth at an angle to each otherinteract with one of the cutting regions,

c) in each starting effective cutting position, a tip of the comminutiontools, forming a first transverse cutter, is oriented toward a tip of atooth of the rigid cutting tools, forming a second transverse cutter, soas to be offset in parallel and cutting past, as a result of which the,besides the cutting forces produced between the cutting regions of thecomminution tools and the cutting edges of the rigid cutting tools, anadditional breaking edge, also arranged parallel to the axis of theshaft, with a parallel offset notching action on the material and actingspecifically highly is obtained, and

d) the material is subjected to an active and additional comminutionprocess with the aggressive participation of the teeth of the rigidcutting tools.

In a further development of the invention, the comminution tools areoffset in relation to one another in the axial direction on the shaft orare arranged with a different radial spacing, the teeth on the rigidcutting tools also being arranged accordingly, which cutting tools runas a slab, as it is known.

Furthermore, the shaft has disks on which the comminution tools arearranged or formed. These comminution tools interact with the teeth,specifically intermeshing between the rigid cutting tools of the slabarranged at intervals.

In order to be able to install and dismantle the shaft in a beneficialway, it has journals on both sides which are detachably connected to theshaft and, if appropriate, form a bearing region. In this case, thejoint can be configured such that it is made by means of a flange.

The housing is of double-walled design at the ends and, in betweenthese, a disk connected to the shaft and sealing in the manner of alabyrinth against the emergence of material is provided, which canexpediently be formed by the flange.

The cutting contours of the teeth of the rigid cutting tools configuredin the manner of a saw can be formed by wearing elements which, forexample, can be replaceable.

In support of the advantages which result from the actions according tothe invention, such as

-   -   increasing the level of comminution,    -   increasing the throughput and    -   reducing the power consumption        in order to improve the efficiency of the comminution machine,        for the further optimization of the comminution process, use is        also made of a controller which obtains its reference variables        from at least one gradient of a parameter of the comminution        process.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail below using an exemplaryembodiment. In the drawings:

FIG. 1 shows a longitudinally sectioned side view of the comminutionmachine,

FIG. 2 shows a plan view according to FIG. 1,

FIG. 3 shows the cross section corresponding to FIGS. 1 and 2 in asimplified representation of the features important to the invention ofthe phases of the active principle of the invention between thecomminution tools and the rigid cutting tools in the operating phase ofthe material put in and not yet comminuted,

FIG. 4 shows the cross section analogous to FIG. 3 in the operatingphase of the started comminution process, and

FIG. 5 shows the cross section analogous to FIGS. 3 and 4 in theoperating phase of the further comminution.

BEST WAY OF IMPLEMENTING THE INVENTION

A comminution machine according to the invention for domestic waste,bulky waste or wood, according to FIGS. 1 and 2, comprises a housing 1having two shafts 2 mounted therein and driven in opposite directions.Arranged on the shafts 2 are disks 2.1 which have comminution tools 3.These comminution tools are lined up in a row at intervals from oneanother on the shafts 2 such that they operate offset in parallel ininteraction with rigid cutting tools 4, which run as a slab in the axialdirection of the shafts 2, and comminute material 5 put in via areceiving element 1.2 in a cutting manner.

As compared with the known prior art, it is important for the technicalrequirement on the comminution machine that imaginary extensions of thecutting edges 4.1 (FIGS. 3 to 5) of the rigid cutting tools 4 do notintersect the axis of the shafts 2 or regions around the axis.

This requirement is aimed at the fact that, in interplay of thecomminution tools 3 with the rigid cutting tools 4, the material 5 canbe taken in a differentiated manner, conveyed and, fixed against therigid cutting tools 4, comminuted with specifically low forces. Thismeans that the efficiency of the comminution machine with regard to thecomminution process is increased substantially as compared with theconventional shredders.

In accordance with FIGS. 3 to 5, the comminution tools 3, in each caseseen in a direction of rotation of the shaft 2 and in their crosssection, have two cutting regions 3.1, 3.2 which are configured suchthat the stability of the comminution tools 3 is not endangered.

An inner cutting region 3.1 takes more material 5 to be comminuted andacts with a relatively short lever arm, and an outer cutting region 3.2takes less material 5 to be comminuted and acts with a relatively longlever arm. In this case, the contours 3.3 of said cutting region 3.1,3.2 in each case describe a concentric circular arc about the shaft 2 inthe direction of the axes of the shafts 2.

Basically, with this design implementation, the preconditions are givenfor using the available forces more effectively than hitherto for thecomminution process of the respective material and in a moredifferentiated manner.

In a functional correspondence with this, the rigid cutting tools 4 havea plurality of teeth 4.2 arranged in the manner of a saw. Thus, twoflanks 4.3 of the teeth 4.2 at an angle to each other interact with atleast one of the cutting regions 3.1, 3.2 in such a way that therespective material 5 is always clamped in and is notched and cutcomprehensively by the available edges of the cutters.

Added to this, and fusing functionally with this effect, is the factthat in each starting cutting position becoming effective a tip of thecomminution tools 3, forming a respective first transverse cutter 3.4,is oriented toward a tip of a tooth 4.2 of the rigid cutting tools 4,forming a respective second transverse cutter 4.4, so as to be offset inparallel and cutting past. As a result, besides the cutting forcesproduced and acting between the cutting regions 3.1 and 3.2 of thecomminution tools 3 and the cutting edges 4.1 of the rigid cutting tools4, an additional breaking edge, also arranged parallel to the axis ofthe shaft 2, with a notching action offset parallel to the respectivepiece of material 5 and acting specifically highly is obtained.

This combination of features thus subjects the material 5 to an activeand additional comminution process with the aggressive participation ofthe teeth 4.2 of the rigid cutting tools 4.

Conclusively in relation to the increased requirements placed and to theobject set in accordance with the invention, this comminution machine isbetter suited to the types of material 5 outlined at the beginning incomminution practice, in that

-   -   the stability of the comminution tools 3 is increased,    -   the level of comminution and the throughput are increased,    -   the power consumption is reduced        and, finally, the comminution process of a “shredder” is        supported.

The improved actions of the comminution machine according to theinvention can be gathered from FIGS. 3 to 5 in three phases illustrated:

-   -   According to FIG. 3, the illustration shows schematically how        the material 5 can be taken in different volumes by cutting        regions 3.1, 3.2 acting with different lever arms and can be        distributed to the rigid cutting tools 4 between the two flanks        4.3 in such a way that the comminution is prepared optimally.    -   With FIG. 4, it becomes clear how, in a functional fusion,        firstly of the actions of the cutting regions 3.1, 3.2 against        the cutting-edges 4.1, the material 5 clamped in the flanks 4.3        is cut and, secondly, is subjected to the corresponding actions        of the first transverse cutters 3.4 with the second transverse        cutters 4.4 and the additional breaking edge effect.    -   Finally, FIG. 5 shows in particular the phase in which the outer        cutting regions 3.2 having the long lever arm and the less taken        material 5 act against the rigid cutting tools 4.

While maintaining the active principle according to the invention andassisting the matter further, according to FIGS. 1 and 2, thecombination tools 3 are arranged offset radially from one another in theactual direction on the shafts 2. Not illustrated in the figures is thepossibility that the combination tools 3 are arranged in a differentangular position on the shafts 2, that is to say axially in the cuttingprofile, for example running conically. The teeth 4.2 of the rigidcutting tools 4 running axially as a slab also have to be arrangedcorrespondingly.

The technologically beneficial implementation for the production, theoperation, the maintenance and repair of the comminution machineaccording to the invention is achieved with the features furtherillustrated in FIG. 1. For this purpose, the shafts 2 have journals 2.2with a bearing region at the ends. The joint between the journals 2.2and the shafts 2 is made by means of flanges 2.3.

For operation in practice, in order to assist optimal comminution andreliability of the comminution machine, it is important that no material5 penetrates through components to be sealed off from one another.Therefore, the housing 1 according to FIG. 1 is designed with a doublewall 1.1 at the ends, in which the journals 2.2 or ends of the shaft 2have a disk seal 2.4, which forms a sealing labyrinth with the doublewall 1.1. The disk seal 2.4 is technologically advantageously formed bythe flange 2.3.

In order to protect the rigid cutting tools 4 against wear, it isbeneficial, as indicated in FIGS. 3 to 5, to equip the cutting contours4.5 with wearing elements 4.6.

COMMERCIAL APPLICABILITY

In all of the features claimed, a comminution machine designed accordingto the invention is optimally able to meet the increased requirements onthe comminution of material of the types described, for this purposemeans also being provided with which the gradient of a parameter of thecomminution machine is registered and used as a reference variable forthe control of the comminution machine.

LIST OF DESIGNATIONS

-   1=Housing-   1.1=Double wall-   1.2=Receiving element for material-   2=Shaft-   2.1=Disk-   2.2=Journal-   2.3=Flange-   2.4=Disk seal-   3=Comminution tool-   3.1=Inner cutting region, short lever arm-   3.2=Outer cutting region, long lever arm-   3.3=Contour-   3.4=First transverse cutter-   4=Rigid cutting tool-   4.1=Cutting edge-   4.2=Tooth-   4.3=Tooth flank-   4.4=Second transverse cutter-   4.5=Cutting contour-   4.6=Wearing element-   5=Material

1. A grinding machine, comprising: a housing having a receiving elementwhich receives material; at least one shaft which is axially mounted inthe housing; a plurality of grinding tools connected to the at least oneshaft in an angular position in an axial direction of the least oneshaft, each grinding tool having a first transverse cutter, an innercutting region and an outer cutting region such that the inner cuttingregion is configured to receive from the receiving element a firstamount of material and the outer cutting region is configured to receivefrom the receiving element a second amount of material, the innercutting region having a shorter lever arm than the outer cutting region;and a plurality of rigid cutting tools arranged within the housing in afixed position on opposing sides of the least one shaft, each rigidcutting tool having teeth and a second transverse cutter wherein the atleast one shaft rotates the plurality of grinding tools such that theinner cutting region grinds the amount of material against the teeth ofthe rigid cutting tools, the outer cutting region grinds the otheramount of material against the teeth of the rigid cutting tools and thefirst transverse cutter orientates in an offset parallel position towardthe second transverse cutter to grind material between the firsttransverse cutter and the second transverse cutter.
 2. The grindingmachine of claim 1, wherein the plurality of grinding tools are offsetin relation to one another in the angular position in an axial directionof the at least one shaft.
 3. The grinding machine of claim 2, whereinthe plurality of grinding tools are arranged in a radial spacing withrespect to the axis of the at least one shaft.
 4. The grinding machineof claim 3, wherein the teeth of the rigid cutting tools extend offsetparallel in the axial direction such that the first transverse cutter isoriented toward the second transverse cutters grind the material in anoffset parallel action.
 5. The grinding machine of claim 1, wherein theat least one shaft has disks on which the grinding tools are arranged;wherein the grinding tools intermesh between the rigid cutting tools andact against the rigid cutting tools in a cutting manner.
 6. The grindingmachine of claim 1, characterized in that wherein the at least one shafthas journals which are detachably joined to the at least one shaft. 7.The comminution grinding machine of claim 6, wherein the journals form abearing region.
 8. The grinding machine of claim 7, further comprisingflanges which form a joint between the journals and the at least oneshaft.
 9. The grinding machine of claim 8, wherein the housing is formedwith a double wall at ends of the housing and, in the interspacetherein, a disk seal connected to the at least one shaft is provided toform a seal.
 10. The grinding machine of claim 9, wherein the seal isformed by the flanges.
 11. The grinding machine of claim 1, wherein therigid cutting tools are reinforced by wearing elements.
 12. The grindingmachine of claim 1, further comprising a means for controlling thegrinding machine wherein a gradient of a parameter of the grindingprocess or grinding machine is registered and used as a referencevariable for control of the grinding machine.
 13. The grinding machineaccording to claim 1, wherein the plurality of rigid cutting tools arefixed within the housing in a position separate from the axis of the atleast one shaft.
 14. The grinding machine of claim 1, wherein the innercutting region and the outer cutting region include contours which forma circular arc about the axis of the at least one shaft in the directionof the axis of the least one shaft.
 15. The grinding machine of claim 1,wherein the second amount of material received by the outer cuttingregion is less than the first amount of material received by the innercutting region.
 16. The grinding machine of claim 1, wherein theplurality of grinding tools are circumferentially connected to the atleast one shaft.